Conventionally, an air conditioner that enables the regulation of the humidity of air using an absorbing agent has been known as a desiccant humidity controller and a desiccant outdoor air conditioning unit. For example, the air conditioning system described in Japanese Patent Publication No. 10-9633 is disposed with two desiccants (absorbing agents) and performs an absorbing operation and a regeneration operation with each desiccant in batches. The air conditioning system also performs dehumidifying air conditioning in a room by repeatedly performing regeneration of the first desiccant and dehumidification of process air by the second desiccant, and dehumidification of process air by the first desiccant and regeneration of the second desiccant, for example.
The humidity controller described in Japanese Patent Publication No. 2004-60954 also performs a dehumidifying operation or a humidifying operation by alternately switching between a first operation, where an absorbing operation is performed by a first absorbing element (a unit including an absorbing agent) and a regenerating operation is performed by a second absorbing element, and a second operation, where an absorbing operation is performed by the second absorbing element and a regenerating operation is performed by the first absorbing element, and supplying first air of the absorbing side or second air of the regenerating side to a room.
Further, the following methods have been proposed in regard to controlling the capability of the dehumidifying and humidifying operations of a desiccant-type outdoor air conditioning unit using a conventional absorbing agent.
(1) As a control method that uniformly regulates the temperature of regeneration air, a method of controlling the operation of a heat pump that serves as a heat source for regenerating the desiccant on the basis of the humidity and temperature of an air-conditioned space is described in Japanese Patent Publication No. 9-318128.
(2) As a control method resulting from deciding the temperature of regeneration air from a set value and a measured value of indoor air humidity or supply air humidity, a method of performing capability control using means which controls the moisture absorption rate of the desiccant in a process air path and means which accelerates a rise in the temperature of the regeneration air in a regeneration air path is described in Japanese Patent Publication No. 10-54586.
The means which accelerates a rise in temperature of the regeneration air raises the temperature of the regeneration air by reducing the flow volume of the regeneration air in the path of the regeneration air, and raises the temperature of the regeneration air using auxiliary heating means disposed upstream of the desiccant in the regeneration air path. The means which controls the absorption rate controls the moisture absorption rate by stopping the circulation of the process air in the process air path and controls the moisture absorption rate by causing the process air to circulate in a bypass path that bypasses the process air from downstream of the desiccant disposed in the process air path to upstream.
Moreover, as another control method in regard to the capability of the dehumidifying and humidifying operations, a method resulting from supply and exhaust air flow volume balance control is also conceivable.